Fix types to accept properties or child at once

Closes GH-24.

Co-authored-by: JounQin <8336744+JounQin@users.noreply.github.com>

Author: wooorm

lib/create-h.js

@@ -92,16 +92,8 @@ export function createH(schema, defaultTagName, caseSensitive) {
    * @overload
    * @param {string} selector
    *   Selector.
-   * @param {Properties} properties
-   *   Properties.
-   * @param {...Child} children
-   *   Children.
-   * @returns {Element}
-   *   Element.
-   *
-   * @overload
-   * @param {string} selector
-   *   Selector.
+   * @param {Child | Properties | null | undefined} [properties]
+   *   Properties (or first child) (default: `undefined`).
    * @param {...Child} children
    *   Children.
    * @returns {Element}

test-d/index.ts

@@ -45,6 +45,13 @@ expectType<Element>(h('', {p: {x: 1}})) // Style
 // @ts-expect-error: not a property value.
 h('', {p: {x: true}})
 
+declare const propertiesOrNullish: Record<string, string> | null | undefined
+expectType<Element>(h('', propertiesOrNullish))
+expectType<Element>(h('', propertiesOrNullish, 'a'))
+declare const propertiesOrChild: Record<string, string> | string
+expectType<Element>(h('', propertiesOrChild))
+expectType<Element>(s('', propertiesOrChild))
+
 expectType<Element>(
   s('svg', {viewbox: '0 0 500 500', xmlns: 'http://www.w3.org/2000/svg'}, [
     s('title', 'SVG `<circle` element'),